TORONTO — Sheldon Hargrove confesses to being "freaked out" by scenes from a mall that he witnessed recently: women using lipstick testers on their lips.

"I couldn't believe that these women were walking up, grabbing a lipstick tester that had been used by everybody else that had walked through the mall, and shlepping it right onto their lips," said Hargrove, director of George Brown College's Yorkville School of Makeup and Esthetics.

"I was in shock, actually."

Proper makeup hygiene is something that his students have drilled into them at the school, one of the largest in the country devoted to the art of makeup and esthetics.

Testers at store beauty counters are available so that a shopper can put some on her hand to see if the colour is a good match for her skin tone, Hargrove said.

"They're not meant to grab and actually start applying to your naked lip."

Lipstick shopping aside, many women could benefit from taking a good hard look inside their cosmetics bag, and checking for hazards that might be lurking within.

"I've seen ladies get eye infections like sties and whatnot - I'm convinced it's from holding on to a mascara too long, or perhaps from not cleaning their brushes properly," Hargrove said.

"For the most part, at worst I've seen someone who might have an allergic reaction to a particular makeup line that perhaps has too much perfume in it."

Dr. Jason Rivers, a professor of dermatology at the University of British Columbia, said the main problems he sees related to makeup are "irritancy issues" and allergic contact dermatitis.

"Infection is usually less common today because people for the most part are using products that have good preservative levels in them," he said. "You don't see a large overgrowth of bacteria or fungus."

A variety of preservatives are allowed for use in North America for the purpose of protecting the skin, he said.

"Some of these systems are formaldehyde-releasing agents, so in some people, it's actually the preservatives themselves which can cause allergic reactions," Rivers said.

Some people are sensitive to nail polish, he noted, and that might manifest itself not on the hands or around the nails but on the face, particularly around the eyes.

"The reason being is that people in general have thinner skin on the face than around the fingers, and that plays a big role in that," he said.

"If you're allergic to an ingredient in a nail polish . . . it will cause an allergic contact dermatitis in sensitized people on the face."

Some individuals are allergic to an ingredient in permanent hair dyes, he added, and dermatitis "can start on your head and neck region, and become more widespread."

Oral and topical steroids are then needed to "settle things down."

Anyone who has ever suffered a bad reaction to cosmetics can take heart from Health Canada regulations that took effect this month, making it mandatory for manufacturers to list ingredients in their products.

The regulations will be phased in over the next two years to allow cosmetics companies time to use up current stock while designing new labels for the ingredients, said Health Canada spokeswoman Renee Bergeron.

Labelling will conform to a system called the International Nomenclature of Cosmetics Ingredients, or INCI, already used in many other countries and designed so that consumers and health-care providers can recognize one accepted term for a problematic ingredient and not have to remember a number of different technical or trade names.

"A lot of people are sensitive to certain ingredients, and if you have sensitive skin or somebody who may be allergic to any kind of ingredient, they need to know about it," Bergeron said.

Eyes, of course, are especially vulnerable.

Dr. Allan Slomovic, a cornea specialist at Toronto Western Hospital, said that when some mascaras break down, formaldehyde is released - and there are people who will experience an allergic reaction to it. Makeup that bleeds into the "tear film" of the eyes can also be a problem.

"Most eyes tolerate it well, and it's not an issue," he said. "But there are other patients who have underlying eye problems - the two most common ones are blepharitis, which is an inflammation of the lid margin, and dry eye. People with both of those problems would be a little less tolerant of makeup, especially mascara which gets into the tear film."

"They can experience irritation, burning, redness, like a foreign-body sensation," said Slomovic, pointing out that if glands on the lid margin are covered by mascara, the eyes could be irritated.

Incorrect application is also a concern.

"I saw someone who actually scratched their cornea with the mascara and it ended up in a bad ulcer, which we treated effectively, but there was still some scarring afterward," he said.

Slomovic strongly recommends that women discard their mascara after three months.

Sharing mascara is also a no-no, because of the possibility of spreading pink eye. A herpes simplex lesion would be another worry.

It "may be relatively asymptomatic, and you may not even know that you had one," said Slomovic, who is chair of the Canadian Cornea-External Disease and Refractive Society. "And you could spread that by sharing mascara."

At the Yorkville esthetics school, where bright unforgiving lights shine down on the chairs where students practise their craft, there is no forgiveness for faulty hygiene.

The aspiring makeup artists are being trained in how to do complete makeup without their hands ever touching the client. Foundations are done with foundation brushes, lipsticks are mixed on a palette with a spatula.

"You have to be very cautious," said Hargrove. "It's OK if a lady's the only one using her own mascara. But when it comes to a makeup artist sharing mascara, you always have to use disposable wands. And you can only dip that wand into the makeup container once, and then it's disposed of. So the wand is never in the product twice. Very critical."

And perhaps on a par with his lipstick tester story, Hargrove shares another bad memory.

"I have actually seen a makeup artist, this was years ago, spit into a product and then start mixing it onto a brush and applying it onto a client's face," he said, visibly recoiling at the recollection.

"Absolute horror."

It's a good idea to clean out your makeup bag every so often, toss some items and start fresh. Here are some recommendations:

• Mascara: Although a retailer might say it's good for a year, Sheldon Hargrove, director of George Brown College's Yorkville School of Makeup and Esthetics, suggests throwing it out within six months. Dr. Allan Slomovic, an ophthalmologist, recommends replacing mascara every three months.
• Lipstick: Should last one to two years, says Dr. Jason Rivers, a UBC dermatologist. Hargrove says if it "starts to get a nasty sort of rancid smell, it's time to pitch it." As for lip liner, Rivers says you can give it up to three years. Lip gloss: six months.
• Foundation: Some companies are starting to print an expiry date on the bottle, usually giving it a two-year shelf life. "There's no absolute rule of thumb," says Hargrove. Higher-end products have silicone added for spreadability and durability, he says.
• Powders: These can last a long time, the experts agree.
• Creams and lotions: If a cream comes with a screw-top lid and multiple people are using it without washing their hands, Rivers says "it's possible to transmit infective agents that way, assuming the exposure period is fairly short." Otherwise, the preservatives will in general "keep things quiet." Using a pump dispenser for lotions so that hands aren't directly in contact with the contents reduces the likelihood of exposure to bacteria.
• Makeup brushes, powder puffs: Should be washed once a week with a mild soap or shampoo, suggests Hargrove. "Let it air-dry overnight." A well-made brush can last 10 to 15 years. Makeup artists use a heavy-duty cleanser on brushes every time they finish an application because they have to use their brushes on numerous people, he says.